Function key button configuration for a handset



FIG. 1 is a front view for a function key button configuration for a handset showing my new design;

FIG. 2 is a front view thereof with the front cover shown in an open position; and,

FIG. 3 is a perspective front view thereof with the front cover shown in the open position.

The broken line showing of the remainder of the handset is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a function key button configuration for a handset, as shown and described. 